Discharge device for the lower stratum component from fluidpervious reciprocating stratifying tables



1947. B. M. BIRD 2,426,337

DISCHARGE DEVICE FOR THE LOWER STRATUM CQHPQNENT FROM FLUID-PERVIOUS RECIPROCATING STRATIFYING TABLES mm Feb. 24,, 1945 Fly 1 INVHVTOR, BYEON M. Bus-2D,

ATT'Y Patented Aug. 26, 1947 DISCHARGE DEVICE FOR THE LOWER STRATUM COMPONENT FROM FLUID- PERVIOUS RECIPROCATING STRATI- FYING TABLES Byron M. Bird, Columbus, Ohio, assignor, by mesne assignments, to The Jeffrey Manufacturing Company, a corporation of Ohio Application February 24, 1945, Serial No. 579,583

1 Claim. 1

This invention relates to a fiuid-pervious stratifying table for separating granular materials of different specific gravities.

An object of the invention is to provide an improved device of the above mentioned general type for separating materials of difierent specific gravities in an efllcient manner and particularly in the provision of a novel arrangement of parts in which very efficient means is provided for drawing off the high-gravity material while maintaining a bed of such material of substantially predetermined depth.

Other objects of the invention will appear hereinafter the novel features and combinations being set forth in the appended claim.

In the accompanying drawings,

Fig. 1 is a side elevational view, more or less diagrammatic, which shows a fluid-pervious stratifying table incorporating the features of my invention; and

Fig. 2 is a transverse view thereof showing particularly the bed of material in section.

In the embodiment of my invention illustrated in the drawings I provide a base In which preferably forms a main air or fluid chamber and derives air or fluid from a source which is illustrated as a fan II. A motor driven rotary valve 12 is provided in the feed pipe leading from the fan II to the chamber H] to provide a pulsating characteristic to the fluid flowing to the chamber ill and ultimately through the bed of material for stratifying. In some embodiments of my invention the valve l2 will be eliminated, in which case the air or fluid flow through the bed will be substantially constant instead of pulsating. Furthermore, in certain broader aspects of my invention the stratifying fluid may be a liquid such as water, in which case the chamber Ill will derive liquid under pressure from any desired source. In this instance the liquid may flow through a valve similar to valve l2 or not, depending upon whether or not it is desired to have it pulsating or non-pulsating in character as it flows upwardly through the bed of material.

As illustrated diagrammatically in the drawings the base i is provided with a pair of laterally spaced upwardly extending supports l3 on the tops of which there are rigidly attached I- members I4 which act as rails to support and guide four rollers in the form of a pair of rear rollers 15 and a pair of front rollers l6 which are" carried in appropriate brackets rigidly attached to the bottom member of a reciprocating deck IT.

The deck ll slopes generally from the feed end to the discharge end as clearly illustrated in Fig.

1 of the drawings. Vibratory or reciprocatory motion is imparted thereto by any desired mechanism such as an eccentric or crank mechanism [8 which may be driven by an electric motor or other appropriate driving device. As one illus-' tration of the frequency and stroke of the deck I! as determined by the vibrating mechanism IE it may have a frequency of to strokes per minute at inch. The slope of the deck may be determined within wide ranges and as one illustration it may be approximately inch to a foot.

The table is designed primarily to treat and clean fine material such as fine coal or fine ore. For example, it may treat minus Ill-mesh coal. The deck I! is constructed by a bottom plate or member I 9 and a pair of longitudinally extending side boards 20 the tops of which form dams, the height of each of which is made adjustable by an individual vertically adjustable supplementary side or dam board 2|. Spaced inwardly of each of the side boards 20 and dam boards 2| is an upwardly and longitudinally extending seal board 22. The top of each seal board 22 is above the adjacent portion of its associated dam board 2| as well as spaced inwardly therefrom and the bottom thereof is below the top of the adjacent portion of said dam board 2|, as clearly illustrated in Fig. 2 of the drawings. As a. consequence there is what may be termed a dam-and-seal draw adjacent each lateral edge of the deck ll, operation of which is described in detail hereinafter.

The bottom portion or base of the deck I! is formed into a plurality of individual open topped cells or chambers 23 which are made by a plurality of transversely and upwardly extending partitions 24 which intersect a plurality of longitudinal and upwardly extending partitions 25. The longitudinal partitions 25 extend between rear and front end boards of the deck I! and the transverse partitions extend between the side boards 20 thereof. These partition 24 and 25 are rigidly connected to and form a part of the deck l'l.

Forming th material supporting portion of the deck I1 is a perforate plate or screen 26 which extends longitudinally the entire length.

of the deck ll between the front and rear plates thereof and which extends transversely between the side boards 20. The plate or screen 26 is supported on the tops of the partitions 24 and 25 and in the preferred embodiment of my invention the plate 26 slopes downwardly from a peak, ridge or high point adjacent the longitudinal center of the deck I! to the ide boards 20. Each side of the plate or screen 26 formed from the longitudinal high point thereof to its lower edge lies in a single plane which is inclined laterally to the longitudinal axis of the deck H.

The material to be cleaned such as fine raw or previously treated coal, is delivered to a feed hopper 21 at the upper end of the deck I! and flows over the perforate plate or screen 26. As the material thus flows it is subject to stratifying action, a hereinafter described more completely, and ultimately the clean coal is discharged over a discharge chute 28 and the refuse is collected in lateral troughs 29, there being one on each side of the deck H, and discharged over refuse chutes 30. If desired, troughs 29 may be subdivided to segregate a high-gravity and middling product. Where coal is the material being treated the clean coal is, of course, the low-gravity material and the refuse is the high-gravity material. If ore i being treated the high-gravity material is the concentrates or values while the low-gravity material is the refuse or gangue.

To provide for supplying a controllable amount of air or other fluid to each of the cells 23 and thus to control the amount of fluid which flows upwardly through each sectionalized portion of the perforate plate or screen 26 I provide an individual conduit or pipe 3| between the chamber Ill and each cell 23. The central portion of this conduit or pipe 3| is preferably made of flexible tubing, as clearly illustrated in Fig. 2 of the drawings, and each pipe or conduit 3| is provided with an individually controllable or shut-off regulating valve 32 which can adjust the fluid fiow'to each cell 23. It is to be particularly noted that there is a partition 25 on each side of the deck I! which is substantially directly below each seal board 22. This is particularly desirable to the end that the amount of fluid which is directed upwardly through the bed of material which is outside each seal board 22 may be adjusted, as it is generally desirable to deliver fluid at a greater rate through this material than through other portions of the bed. In other words, the fluid flow through the material within the dam-andseal draw i preferably greater than through the other portions of the bed.

In the operation of the device the material, which is made up of constituents of different specific gravities such as high-gravity refuse found in coal including shale and bone coal and low-gravity material such as pure coal particles, is fed by way of the feed hopper 21 onto the material supporting portion of the deck I! represented by the perforate plate or screen 26.

The vibratory or reciprocatory motion imparted to the deck I! in itself will tend to produce a certain amount of stratifying action and what is of considerable importance will impart at least to a considerable extent a fluid or mobile characteristic to the bed of materials. After the device has been in operation for a while, the bed of materials, under the combined action of the vibratory motion and the upward flow of fluid, whether it is constant or periodic, will tend to stratify with high-gravity material forming the lower stratum and the low-gravity material or coal forming the top stratum.

At the discharge end, the material will be banked against a banking board 33 which will act to prevent the refuse or high-gravity material from flowing into the discharge chute 28. The high-gravity refuse will form on the perforate plate or screen 26 along the general lines illustrated in Fig. 2 of the drawings and due to the extremely fluid characteristic of all the material forming the bed, which bed as a whole may be designated 34, it is evident that the material in each of the draws 2|, 22 will be subject to what is similar or substantially equivalent to a hydraulic head produced by the bed of materials which is between the seal boards 22 and which has a greater height than the dam boards 2|. As a consequence, the dam-and-seal draws 2|, 22 will act automatically and without any reciprocating or moving parts, relative to the deck ll, so as to maintain a substantially uniform depth of refuse bed assuming a substantially uniform depth of total bed 34. In other words, the damand-seal draws require no special moving parts with respect to the deck ll. However, due to the reciprocation of said deck I! or more broadly stated due to the fluid character of the bed 36, including articularly that portion which is in the dam-and-seal draws 2i and 22, said draws act automatically to discharge the refuse or highgravity material at such a rate as to maintain a predetermined ratio between the depth of the refuse or high-gravity portion and the low-gravity or clean coal portion of the bed 36. In other words, the apparatus disclosed performs in an automatic and very efficient manner to separate materials, particularly flne materials, of different specific gravities and involves an improved mechanism and process for carrying this out.

From the foregoing it will be obvious that I have provided an improved stratifying table for separating granular materials of diflerent specific gravities wherein materials to be separated are fed to a deck from which materials of high specific gravity are discharged at the sides and material of lowest specific gravity is discharged at a lower end over a banking board or dam. The deck includes a base which forms a plurality of open topped cells or chambers and a central top ridge which extends throughout the length of the base and over which there is a screen adapted to form a top for the base and to support materials fed to the deck. The deck is reciprocated lengthwise of its central ridge in a plane sloping from its feed end whereby materials supported by the screen will be agitated and caused to flow downwardly thereover with the materials of greater specific gravity also flowing outwardly to each side of the central ridge to dam-and-seal draw structures one of which extendsalong each side of the base. Each of the dam-and-seal draw structures includes an upright seal board positioned inwardly of the edge of the screen and spaced above it under which high specific gravity material to be discharged from the deck must pass, an upright dam board positioned adjacent the edge of the screen over which high specific gravity material must spill to be discharged from the deck, and an outer trough for receiving material spilled over the dam board. Means is provided for creating a flow of fluid to each of the cells or chambers below the screen whereby the fluid, which may be either air or water having a constant or pulsating flow, is caused to flow upwardly through the screen for causing stratiflcation of the materials thereabove and to flow with a greater velocity than the average of the velocities of flowing fluid in the other cells or chambers upwardly from. cells or chambers positioned below the screen and between the dams and seals for assisting in lifting the high specific gravity material to be discharged from the deck over the dams.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claim hereto appended and I wish therefore not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

A stratifying table for separating granular materials of different specific gravities having a deck including a base, said base having a central top ridge extending throughout its length and being formed to include a plurality of open topped cells, screen means above and forming a top for said base adapted to carry a bed of material, a dam-and-seal draw structure extending along each side of said base including an upwardly extending dam means positioned adjacent the edge of said screen and seal means positioned above said screen and inwardly of said dam means, said base including cells positioned between said dam-and-seal means, trough means extending along the outside of said dam means adapted to catch material spilled over said dam,

means movably supporting said deck in an inclined plane. with respect to its length, means for flow upwardly through said screen means, said last named means including means for creating fluid flow, and means for conveying flowing fluid the troughs, the greater velocity of the fluid adjacent the dams assisting in lifting the material of greater specific gravity thereover.

BYRON M. BIRD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,289,845 McCarthy Dec. 31, 1918 1,943,800 Revelart Feb. 27, 1934 2,161,500 Bird June 6, 1939 2,275,849 Fraser Mar. 10, 1942 FOREIGN PATENTS Number Country Date 798,731 France Mar. 11, 1936 

